Mammals of the periglacial hyperzone of the end of the Pleistocene and formation of the modern rodent fauna in the mountains of Western and Middle Siberia

The fossil and modern faunas of small mammals from the end of the Pleistocene to modern times in the south of West and Middle Siberia were analyzed. It was shown that during the Sartan, the typical hyperborean complex of mammals was spread to the middle reaches of the Yenisei. In the northwest of Altai a hyperborean complex of mammals of the southern type existed at the end of the Pleistocene; it had its specific regional features. Warming and an increase in humidity in the Holocene led to the disappearance of the periglacial landscape and reduction of the area occupied by the tundra-steppe ecotopes. Expansion of the forest belt resulted in degradation of the hyperborean complex of mammals. In the second half of the Holocene, the formation of forest and forest-steppe complexes of small mammals took place.